One Doc Flashcards
Complications associated with 12mm overjet, well aligned arches and ectopic canines.
Trauma risk to anterior teeth, difficulty speaking, eating, psychological factors ie teasing, root resorption of adjacent teeth.
Dental complications of a retainer
Fixed - can debond, wire can fracture, difficult to keep clean, higher gingivitis risk.
Removable - thermoplastic - can be lost, can later occlusion, chip or fracture, compliance.
Posterior cross bite URA appliance design
Aim: Correct posterior cross bite.
A - Midline palatial screw.
R - Adams clasps on 4’s and 6’s.
A - Yes.
B - self cured PMMA and posterior bite plane.
What does right deviation of mandible on closing mean and what are the 2 problems associated if untreated
Mandibular displacement on closing due to inter-arch width discrepancy - due to inter-arch width discrepancy, the teeth naturally occlude in such a way that the posterior teeth are cusp to cusp, and therefore the patient needs to deviate their mandible to a side to achieve intercuspation.
TMD, parafunctional habit, toothwear.
Name 4 fluoride supplements that could be given to a patient with a fixed appliance.
Toothpaste - 1450 ppm.
Fluoride varnish - 22600 ppm 4 times per year.
Fluoride mouthwash - 225 ppm once daily.
Fluoride tablets - 1mg once daily.
2 methods to prevent decalcification other than fluoride supplements
OHI and diet advice, fissure sealants.
List 8 potential risks of orthodontic treatment other than decalcification
Root resorption, relapse, gingival recession, failure to complete, wear of adjacent teeth, ulceration, loss of vitality, mucosal irritation, loss of periodontal support.
How do you assess a patients AP relationship?
Visual, palpate skeletal bases, lateral cephalometric.
4 special investigations an orthodontic specialist would do
Study casts, clinical photographs, lateral cephalometric, OPT
4 intra-oral features of a class III patient
Reverse or reduced OJ, displacement on closure, retroclined lowers, attrition.
What systemic condition is associated with a class III patient in which the mandible keeps growing?
Acromegaly.
Design a URA to correct a 12 cross bite
Aim - please construct a URA to correct the anterior crossbite of tooth 12.
A - Palatal z-spring on 12 - 0.5mm HSSW.
R - Adams clasps on 4’s and 6’s - 0.7mm HSSW.
A - Yes.
B - Self cured PMMA, posterior bite plane.
What 4 characteristics of the dentition 12 anterior crossbite make this ideal for URA treatment?
Enough space, 12 palatally tipped, good OB for stability, only 1 tooth movement required.
What 5 factors can resist displacement forces?
Gravity, mastication, active component, speech, tongue.
Information to include in a referral to an orthodontist
Pt details - name, age, history, radiographs, photographs, skeletal base, incisors class.
Management of a debonded bracket and demineralisation
Account for components, ask the pt if they know what happened, check the health of teeth, deal with problem - if arch wire circular, remove ligature and bracket, if archive square, ensure ligature attached tightly and teach pt to move bracket to side to clean, refer back to ortho, inform pt of decalcification.
Non-compliant patient - option of extraction of incisors and denture provision
Loss of incisors - drifting of incisors, resorption of bone, labial profile.
Denture - plaque retentive factor, increased perio risk, aesthetic, psychological.
Uncompliant patient - why are crowns not indicated?
Destructive crown prep, OH not satisfactory enough.
OHI in high risk pt
5000ppm toothpaste, ID cleaning, disclosing tablets, spit do not rinse, 2 mins, modified bass technique, 2x daily.
What are the uses of a URA
Tooth tipping, habit breaker, space maintainer, reduce OB, expand arch, retainer.
Design a URA to reduce 8mmOJ and OB - 4’s missing
Aim: Please construct a URA to reduce the OJ and OB.
A - 22, 21, 11, 12 - roberts retractor - 0.5mm HSSW and o.5mm ID tubing. 13 + 23 mesial stops - 0.7mm flattened HSSW.
R - 16 and 26 - Adams clasps - 0.7mm HSSW.
A - moving 4 teeth - not ideal, but okay.
B - Self cure PMMA - FABP - OJ+3mm.
Anchorage for arch widening
Reciprocal anchorage.
Give 6 bits of advice when delivering a URA
Worn 24/7 including mealtimes, will be uncomfortable, increased saliva, bulky, speech difficulties, brush dry toothbrush after meals, remove and store safely when playing contact sports, avoid fussy drinks, hot and sticky foods, give emergency contact details.
Outline the delivery of a URA
Check correct pt and appliance, appliance matches design, feel for sharp edges, check integrity of wire work, insert and check for blanching of tissues or trauma, inspect posterior retention, flyover then arrowheads, check anterior retention, activate, show pt insertion and removal and get them to do it, review in 4-6 weeks.
When to treat an anterior crossbite
As soon as detected.
3 features of a URA that are useful in the tax of an anterior crossbite
Single tooth movement, increases OB, self retentive after reverse OJ fixed.
Design URA to correct anterior crossbite
A - 0.5mm HSSW z-spring.
R - Adams clasps 6’s 0.7mm, e’s 0.6mm
A - Yes.
B - self cured PMMA - posterior bite plane.
What is the incidence of hypodontia in the UK
0.6%
What three teeth in order (excluding 8s) are most commonly missing?
mand 5, max 2, max 5.
How may hypodontia present to you as a GDP?
Delayed/asymmetric eruption, infraocclusion, missing primary tooth, ectopic 3, CLP.
What are the treatment options? Hypodontia
Accept and monitor, restorative e.g. bridge, implant, denture, Ortho alone, ortho and restorative.
Name 4 members of the hypodontia multidisciplinary team
Paediatric dentist, orthodontist, prosthodontist, GDP, restorative dentist, oral surgeon, speech and language
therapist, clinical psychologist.
When to palpate canines
9 years old.
How to localise canines
Paralax.
Age range to intervene for ectopic canines
11.
How long after XLA of c should you review
6 months.
Ectopic canine and c extracted but no effect. what are the tx options now?
Open exposure palatal +/- bone removal, Open Buccal apically repositioned flap +/- bone removal, Closed exposure
and gold chain, Surgical extraction of 3
What is a supernumerary tooth
Extra tooth to the permanent dentition
Where is supernumerary teeth most likely to happen
Maxilla between the centrals mesiodens.
Types of supernumerary teeth
Odontome - 2 types, denticles or mass of disorganised dental tissues
Tuberculate - barrel shaped
Supplemental - extra tooth of normal dentition
Conical - peg shaped lateral
Effect of supernumeraries on the permanent dentition
Prevent/delayed eruption (impaction of permanent teeth), Crowding, Failure to erupt, Traumatic eruption, Occlusal
interference.
Intra-oral signs of thumb sucking
Lowers retroclined, Uppers proclined, AOB/Incomplete open bite, Narrow upper arch +/- unilateral posterior crossbite
BSI class 2 div 1
Lower incisor edges occlude posteriorly of upper cingulum, Increased OJ, Upper incisors average or proclined
Functional appliance to reduce OJ - 8 changes/ways it did this
Constant wear, Dento-alveolar compensation (proclined lower incisors, retroclined upper incisors), Growth
modification (promoted mandibular growth, restricted maxillary growth)
What clinical signs indicate impacted canines
Delayed eruption, asymmetrical eruption, retained c, loss of vitality or mobility of 2, discolouration of 2s, distal
tipping of 2, no palpation of 3
Investigated impacted canines
Radiograph → Parallax technique – Vertical w/OPT and Ant occlusal or Horizontal w. 2x periapical. SLOB rule. Can
also use CBCT
Risks of impacted canines
Resorption of 2s, cyst formation, aesthetics
Tx options for impacted canines
- Monitor. 2. XLA C at 10-13years 3. Surgical extrusion of 3 e.g. w/bonded gold chain 4. Autotransplant.
Incidence of CLP in the UK
1/700 births.
What are the general health implications of CLP
Aesthetics, speech, hearing, infection, CVD and associated w/Down Syndrome.
What are the dental features of CLP
Hypodontia, impaction, crowding, Class III, high vaulted and narrow palate, more susceptible to caries.
5 treatment stages for CLP
Lip closure 3 months → palate closure 1 year → bone graft 8-10 years → definitive ortho 15 years → definitive
surgery 18+ years
Name 5 members of the multidisciplinary team for CLP
Maxfax surgeon, ENT, speech therapist, psychologist, geneticist, cleft nurse, dental team
A 10 year old patient in the orthodontic department presents with a class III incisor relationship. What is this?
Tips of lower incisors occlude anterior to cingulum plateau of upper incisors. Overjet is reduced or reversed.
What is dentoalveolar compensation?
The body’s attempt at creating a ‘normal’ relationship between upper and lower arches when not occurring naturally.
E.g. proclination and retroclination of incisors.
4 special investigations for class III patients
Radiographs, clinical photos, study models, Kesling setup, CBCT, sensibility test
Dental features associated with class III skeletal relationship
AP class III, class III canines and molars, AOB, reverse OJ, crowding, crossbite
Treatment options available for class III patients
- Accept and monitor 2. Interceptive orthodontics – URA to correct any anterior crossbite and procline uppers over
lowers. 3. Growth modification – functional appliance e.g. reverse twinblock or headgear. 4. Orthodontic Camouflage
– accept skeletal base and aim for class I incisors with fixed appliance. Pt needs to be able to reach edge-to-edge. 5.
Orthognathic surgery – if severe, Requires fixed appliance before and after.
Name 4 components of fixed appliance
Wire, molar bands, brackets, modules.
How does tooth movement work?
Frontal resorption. Tension side sees bone deposition whilst pressure side sees hyperaemia, leading to increased
osteoclasts and blasts, leading to bone resorption.
Give 4 methods of anchorage
baseplate, transpalatal arch, Nance button, TAD.
Class II div 2 malocclusion
Lower incisor tips occlude anterior to the cingulum plateau of the upper incisors. The upper incisors are retroclined.
The overjet is increased or reduced
Dental features of class II div 2
Class II canines and molars. Retroclined upper incisors, crowding, increased overbite → lower incisors occlude with
uppers or palate
Soft tissue features in class II div 2
High lower lip line, lip trap, trauma to gingiva or palate
Class II div 2 tx options
- Accept and monitor 2. Growth modification w/ twin blocks 3. Camouflage but caution w/relapse 4. Orthognathic
surgery if ANB >5
What are the common complications of orthodontics?
Relapse, decalcification, root resorption, gingival recessionPain, loss of vitality, trauma, TMD, periodontal disease
How are the risks of ortho tx managed
Relapse → pt education and consent. Advised will require some form of retention e.g. fixed bonded retainer, vacuum
retainer lifelong esp. diastema and rotation. Decalcification → pt education. OHI, Diet, Fluoride. Resorption →
advised pt of risk. Radiographs pre-treatment to assess, not excessive ortho forces to limit. Advised 1mm is normal
Class II div 1
Lower incisor tips occlude posterior to upper incisor cingulum plateau. Upper incisors are proclined or average.
Overjet is average or increased.
Class II div 1 dental features
Proclined upper incisors, increased OJ, class 2 molars, class 2 canines
Soft tissues class II div 1
Incompetent lips, lip trap, tongue thrust.
Class II div 1 tx options
- Accept and monitor. 2. URA → limited role but Robert’s retractor may be used. 3. Growth Modification → Main
use is class 2 Div 1. Twin block, Frankel 3, Headgear. 4. Camouflage 5. Orthognathic surgery
4 reasons for a diastema
supernumerary at midline, high fraenum, natural space, proclined incisors, hypodontia
How are diastemas managed
Accept, rx of cause.
How is a posterior crossbite managed?
URA w/ mid-palatal screw and FABP.
2 ways of expanding arch
Quadhelix, rapid maxillary expansion.
What teeth are most commonly infraoccluded?
Lower Ds (8-14%).
How do infraoccluded teeth appear clinically and radiographically
No physiological mobility, low in arch, metallic percussive note, no PDL radiographically, root resorption (ERR)
Tx options for infraoccluded teeth
If permanent present, monitor for 1 year as usually self fixes. If no change, XLA. If no successor, XLA as will get worse
In lateral cephalometry, what are SNA, SNB and ANB?
SNA – maxilla to anterior cranial base, SNB – mandible to anterior cranial base, ANB – SNA-SNB.
What are the average values for a Caucasian? SNA SNB
SNA - 81 +/- 3, SNB – 78+/-3, ANB – 2 - 4
What is the average FMPA angle?
27
What is average incisors inclination?
109/93°
What is ANB for class II and class III?
Class II >4, Class III <2 or negative.
Give 4 oral signs of a non-nutritive sucking habi
proclined maxillary incisors, retroclined mandibular incisors, localised anterior open bite/incomplete OB, narrow
upper arch +/- posterior crossbite
Explain the effect a prolonged digit sucking habit has on the posterior dentition
The thumb/finger held in the mouth causes the mandible to drop open and the tongue is held in a lower position than
normal. This means the sucking action on the cheeks then narrows the maxillary dentition and causes a crossbite
Give 4 methods of stopping a NNSH
positive reinforcement, removable habit breaker, fixed habit breaker, plaster on finger, gloves, swap for dummy as
less likely to continue past school age, preventative nail varnish
Name 2 syndromes associated with hypodontia
CLP, Down syndrome, Ectodermal dysplasia
What options are available for hypodontia
Accept, orthodontics, restorative, combined orthodontics and restorative, prosthodontics
Name 4 members of a hypodontia MDT
paediatric dentist, orthodontist, restorative dentist, oral surgeon
What is the incidence of missing primary teeth and permanent teeth?
Primary → <1%, Secondary→ 5 - 6
Give 4 types supernumerary and effects
COST – Conical, Odontome (compound or complex), supplemental, tuberculate.
What effects can they have?
Associated with diastema, impacted 1s, cyst formation, displacement, crowding
What 4 factors make early loss of a primary tooth worse?
Age, maxilla, already crowded, tooth (E worst)
When might you consider balancing a primary tooth extraction?
Upper C in a crowded dentition.
Give 4 reasons for an unerupted 1
Supernumerary (tuberculate), trauma to A, crowding, pathology - dentigerous cyst
Tx options for unerupted 1
XLA supernumerary/surgical exposure
Give 4 uses of a URA
Give 4 uses of a URA
tipping teeth, space maintainer, reduce OJ, habit breaker, retainer, expand arch.
Give 6 signs of ‘good wear’ of a URA review appointment
pt arrives wearing URA, pt can take in and out easily, can speak with appliance in, looks worn, active component now
passive, signs of wear on palate, teeth move
Design a URA for: (refer to BDS3 aggregated notes)
1. Retract upper 3s
2. Retract upper 3s and reduce OB
3. Retract buccally placed 3s and reduce OB
4. Correct anterior crossbite of 12
5. Expand upper arch
6. Reduce OJ and OB
REFER
How is antero-posterior skeletal relationship measured? Give values
Visual, palpate bases, lateral cephalometry. I → max 2-3mm anterior to mand. II → max >2.3mm anterior to mand.
III → mand anterior to maxilla
How is vertical skeletal relationship measured? Give values
FMPA angle, Face height, lateral cephalometry. FMPA → Measure Frankfort plane from lower orbit to ext.acoustic
meatus and Mandibular plane along lower border of mandible. Average = 27° ± 4 and meet at occiput. Increased =
before occiput >31°. Decreased = behind occiput <23°
UAFH:LAFH → 50:50 clinically. Measure glabella to subnasale to menton
How is transverse measured?
Symmetry from in front and above.
Define and give values for: oj ob molar relationship, canine relationship, crowding incisor angulation
Overjet – labial most prominent lower incisor to labial most prominent upper incisor. 2-4mm avg.
Overbite – Vertical overlap of incisors. ½-⅓ average.
Molar relationship – MB cusp of maxillary 6 occludes w/MB groove of mandibular 6.
Can be anterior– II or posterior –III.
Canine relationship – Maxillary canine occludes between mandibular canine and 1st premolar. II and III same as
molar relationship.
Crowding – Mild/Mod/Sever → <4mm/4-8mm/>8mm. Measure by overlap or space available vs needed or mixed
dentition analysis.
Incisor angulation – 109/93° avg
Name 5 active components, their measurements and uses
All 0.5mm HSSW. Palatal finger spring → 0.5mm HSSW w.guard. Retract teeth. Buccal canine retractor → 0.5mm
HSSW w/0.5mm tubing. Retract buccally placed canines. Z-Spring → 0.5mm HSSW. Anterior crossbite. Mid-palatal
screw → expand upper arch. Robert’s retractor → 0.5mm HSSW w/ 0.5mm tubing. Reduce overjet
Name 2 retentive components
Name 2 retentive components
All 0.7mm HSSW unless on primary teeth, then 0.6mm. Adam’s Clasp, Southend Claps
Give 2 baseplate modifications
Flat anterior bite plane → allows eruption of posteriors to aid anterior tooth movement. OJ + 3mm. Posterior Bite
plane → allows disclusion.
Give 5 possible treatment options for an impacted mola
monitor as most disimpact alone, orthodontic separators, discing, XLA E if present, URA
Why might a first molar be impacted
Angle of eruption, ectopic crypt, E morphology, small maxill
His mother mentions his primary teeth were very straight. What features of normal development should prevent
crowding of the permanent dentition?
Growth of maxilla and mandible, proclined permanent teeth, natural space between primary teeth.
What is Leeway space?
Natural space provided b
Natural space provided by retention of primary teeth. Approx. 1.5mm/Q in mandible and 2.5mm/Q in maxilla
A patient has a 12mm OJ and ectopic canines – what are the dental complications of this? I
Increased risk of trauma,
difficulty eating/speaking, xerostomia, crowding, aesthetics, displacement
What are the complications of a bonded retainer?
Plaque trap, fracture, debond, ST trauma
What are the complications of a bonded retainer?
Plaque trap, fracture, debond, ST trauma
